Vacuum box with skimmer bladee

ABSTRACT

A process, and an apparatus, for improving sheet properties in a twin fabric paper making machine forming section whereby pressure pulse generation in the stock can be controlled. The pressure pulses are controlled by mounting a vacuum assisted skimmer blade ( 15 ) supported by an adjustable resilient support means ( 18 ) so that its height can be altered, and so that it can respond to transient changes in the stock layer thickness. The resilient and adjustable support means ( 18 ) itself is supported by a vacuum drainage box ( 10 ), which serves to capture at least the major proportion of the fluid skimmed of by the skimmer blade ( 15 ). This apparatus the position of the skimmer blade ( 15 ) to be altered in two ways without stopping the paper making machine. The skimmer blade ( 15 ) can be located either so that it is out of contact with the forming fabric ( 3 ), or so that it can be in contact with the forming fabric. By adjusting the resilient adjustable mounting, the amount of pressure exerted by the skimmer blade ( 15 ) onto the forming fabric surface is controllable, thus controlling the pressure pulses generated by the skimmer blade. The orientation of the skimmer blade can also be controlled, so that rather than the blade surface being substantially parallel to the machine side surface of the forming fabric, it can be angled somewhat with either its leading or its trailing edge pressed into the fabric.

FIELD OF THE INVENTION

[0001] The present invention relates to a process, and an apparatus, forremoving fluid from the machine side of one, or both, forming fabrics inthe forming section of a twin forming fabric paper making machine. It isparticularly concerned with a process and an apparatus to remove andcapture a major proportion of the fluid drained through a formingfabric, by contacting the machine side of one of the forming fabricswith at least one resiliently mounted skimmer blade located between twofixed blades in contact with the machine side of the other formingfabric, for example between two blades supported by a forming shoe. The,or each, resilient mounting is attached to a vacuum box, with theskimmer blade located immediately downstream of an elongate suctionorifice. This invention is thus of use in any twin fabric papermakingmachine having two superposed forming fabrics, particularly thoseequipped with a curved forming shoe.

BACKGROUND OF THE INVENTION

[0002] In the manufacture of paper and board products in a twin fabricpaper making machine, a highly aqueous stock consisting of about98-99.8% water and from 0.2-2% papermaking fibers and other solids isejected at high speed from a headbox slice into the gap between themoving forming fabrics. In the following discussion, for the sake ofsimplicity, it is assumed that the path followed by the twin formingfabrics is more or less horizontal; other arrangements are known andused in which the path is not horizontal and may even be vertical. Insuch machines a direction substantially perpendicular to the two formingfabrics is known as the Z-direction. Further, when the path ishorizontal, one forming fabric is commonly referred to as the “upper”,and the other as the “lower” fabric.

[0003] In a twin fabric forming section, the two forming fabrics eachpass in sliding contact over a plurality of fabric support elementswhich serve to define a path along which the two forming fabrics movetogether; these elements, together with their supporting structures, aregenerally known as forming shoes and the forming fabric path over themmay be straight or curved. The stationary fabric support elements incontact with the machine side of the lower forming fabric may be fixed,or may be adjustable in the Z-direction. In current practice, thestationary support elements in contact with the machine side of theupper fabric are normally not adjustable, while those in contact withthe machine side of the lower forming fabric can be resiliently mountedso as to assist with fluid removal. The resiliently mounted blades arenot used in association with a vacuum box, and rely on gravity to assistwith fluid drainage. Further, the fabric support elements in contactwith each fabric are known to generate pressure pulses within the stockbetween the two forming fabrics as they move together under tensionthrough the forming section. The nature of the pressure pulses generatedin the stock can only be adjusted by changing fabric tension, bychanging the angles of wrap of the fabrics over the fabric contactingsurfaces of a chosen element or elements, by changing a chosen elementor elements, or by physically removing an element or elements. Pressurepulsed benefit the forming process by causing relative motion in thestock layer that breaks apart the fibre flocs and causes the fibers tobecome more uniformly dispersed in the stock layer.

[0004] Fixed elements are unable to react to transient changes in thethickness of the stock layer between the forming fabrics. Such changescan occur when the machine is being started, and also may occur at anytime during normal machine operation. In an extreme case, transientstock thickness variation can result in damage to either, or both, ofthe forming fabrics.

[0005] This invention seeks to provide a process, and an apparatus, bymeans of which the papermaker can control both fluid removal from themachine side surface of at least one of the forming fabrics, and pulseformation in the stock between the two forming fabrics so as to enhance,maintain or diminish the kinetic energy injected into the stock, thusallowing optimized fluid removal and agitation in accordance with papermaking conditions. This invention further seeks to provide an apparatusin which a skimmer blade is resiliently mounted, so that the mountingallows the skimmer blade to respond to transient changes in thethickness of the stock layer between the two moving forming fabrics. Theinvention further seeks to provide an apparatus including a skimmerblade which is resiliently mounted and located immediately downstream ofan elongate suction orifice attached to a vacuum box, wherein theresilient mounting is attached to the vacuum box, and the vacuum box asa unit can be moved away from the path of the forming fabrics as theymove through the forming section.

DISCUSSION OF THE PRIOR ART

[0006] Kade et al, in U.S. Pat. No. 4,865,692, disclose an adjustablesupport structure for a foil blade, for use in a conventional singlefabric open surface forming section, which allows the orientation of theblade relative to the forming fabric to be adjusted. In this structure,two C-section beams are interlocked to provide an essentially S-shapedstructure. The upper C-beam carries the foil blade, and the lower C-beamis mounted onto a drainage box. However, this structure only allows asmall angular change and the axis about which the angle changes is notdefined with any precision.

[0007] Skyttä in EP 0 319 107 discloses a twin fabric forming section inwhich “deck elements” are located opposite fixed elements. Although thedeck elements are rigidly mounted as a group onto either a suction box,or a drainage box, the deck elements are given some resiliency byproviding a resilient mounting for the supporting box. There is nodisclosure of providing a resilient mounting for each individual blade,and the deck element assembly as a unit cannot be moved out of contactwith the adjacent forming fabric.

[0008] Hujala in EP 0373 133 discloses an improvement to the known“Sym-Former R” hybrid forming section. To assist in upward dewatering ofthe upper forming fabric, a rigidly mounted suction-aided doctoringdevice is located within the loop of the upper forming fabric. Theopening of the water receiving orifice is mechanically adjustable, bymeans of a spindle mechanism. The blades located beneath the lowerforming fabric are resiliently mounted, and the pressure they exert onthe lower fabric can be made to increase n the downstream direction.

[0009] Bubik et al. in U.S. Pat. No. 5,262,010 disclose a number ofvaried structures, again intended for use in a single fabric opensurface paper making machine. These structures allow either a singlefoil, or a group of commonly mounted foils, to be moved into contactwith the forming fabric. The stated aim is to stabilize the foil, orgroup of foils, to counteract the tilting forces produced by frictionbetween the foil, or foils, and the moving forming fabric with whichthey are in sliding contact. Although pressurized hoses are used in manyof the disclosed they all appear to involve parts which are in slidingcontact with each other.

[0010] Bubik et al. in CA 2,050,647 (application as filed and published)also disclose a skimmer blade arrangement for use with the upper formingfabric of a twin fabric machine in which the forming section isessentially horizontal. As disclosed, a slot is use to trap fluiddisplaced from the stock upwardly through the upper forming fabric,which is doctored off the fabric by a skimmer blade. The skimmer bladeappears to carried by an “elastic” mounting, but it is unclear how thismounting is constructed. There is no mention of the use of vacuum totrap the doctored off fluid.

SUMMARY OF THE INVENTION

[0011] This invention seeks to provide both a process, and an apparatus,to remove fluid from the machine side surface of at least one formingfabric the forming section of a twin fabric paper making machine.According to this invention, a resiliently mounted skimmer blade isplaced to contact the machine side of one forming fabric at a point thatis between two fixed support elements in contact with the machine sideof the other forming fabric; these fixed support elements may form partof a forming shoe. The resiliently mounted skimmer blade is locatedimmediately downstream of an elongate orifice in the cross machinedirection, which is connected to a vacuum box. The level of vacuum inthe vacuum box is controlled so that the fluid doctored of the formingfabric by the skimmer blade is captured in the elongate orifice, andtransferred to the vacuum box. The fluid therefore cannot fall back ontothe forming fabric and cause defects in the incipient paper web. Theamount of pressure applied to the machine side surface of the formingfabric is adjustable, so that its indentation into the forming fabric,and hence the pressure pulses generated within the stock between theforming fabrics, can be controlled to optimize paper making conditions.The resilient mounting is conveniently attached to the vacuum box, whichis adjustably mounted so that the skimmer blade can be moved away fromthe forming fabric, thus protecting it from major disturbances in stockthickness, such as at machine start up, by moving the entire assemblyaway from the machine side of the forming fabric.

[0012] In this invention, both fluid removal and the pressure pulses arecontrolled by mounting a vacuum assisted skimmer blade supported by anadjustable support means so that its position relative to the machineside of the adjacent forming fabric can be altered. Additionally, inthis invention the ability to respond to transient changes in the stocklayer thickness is provided by fabricating the skimmer blade mounting sothat it is resilient, and allows a limited range of spontaneous movementin the Z-direction. Further, the resilient and adjustable support meansitself is supported by a vacuum drainage box, which serves to capture atleast the major proportion of the fluid skimmed off by the skimmerblade. The apparatus envisaged by this invention allows the position ofthe skimmer blade to be altered in two ways without stopping the papermaking machine. First, by moving the vacuum assisted drainage box, theskimmer blade can be located either so that it is out of contact withthe forming fabric, or so that it can be in contact with the formingfabric. Second, by adjusting the resilient adjustable mounting, theamount of pressure exerted by the skimmer blade onto the forming fabricsurface is controllable, thus controlling the pressure pulses generatedin the stock by the skimmer blade, and the quantity of fluid removed bythe skimmer blade. Additionally, this invention contemplates that morethan one adjustable skimmer blade, each mounted onto its own vacuum boxas a skimmer blade assembly, can be used in a twin fabric formingsection if desired. It is also contemplated that an adjustable skimmerblade assembly may be mounted on either side, or both sides, of the twoforming fabrics in suitable locations. Furthermore, this invention alsocontemplates that the orientation of the skimmer blade can becontrolled, so that rather than the blade surface being substantiallyparallel to the machine side surface of the forming fabric, it can beangled somewhat with either its leading or its trailing edge pressedinto the fabric.

[0013] Thus in a first broad embodiment this invention seeks to providea suction assisted fluid skimmer blade mounting for use in a twin fabricforming section of a paper making machine having a machine direction anda cross machine direction, and including in the forming section twoopposed forming fabrics which move together in the machine direction,each fabric having a machine side surface and a paper side surface, themounting including:

[0014] a vacuum chamber, having an elongate orifice extending in thecross machine direction, to which a controlled vacuum means isconnected;

[0015] a first adjustable support means supporting the vacuum chamber;

[0016] a second adjustable resilient support means carried by the vacuumchamber and adjacent the elongate orifice; and

[0017] a skimmer blade attached to the second adjustable resilientsupport means, the skimmer blade having a fabric contacting surfaceextending in the cross machine direction including a leading and atrailing edge;

[0018] wherein:

[0019] (a) the first adjustable support means is constructed andarranged to allow the vacuum chamber to be positioned in a firstposition where the skimmer blade is out of contact with the firstforming fabric, and a second position where the skimmer blade can be incontact with the forming fabric;

[0020] (b) the second adjustable resilient support means is constructedand arranged to allow movement of the skimmer blade when the vacuumchamber is in the second position to any point between a first locuswhere the fabric contacting surface of the skimmer blade is out ofcontact with the first forming fabric, and a second locus where thefabric contacting surface of the skimmer blade is pressed into themachine side surface of the first forming fabric;

[0021] (c) the vacuum chamber, together with the vacuum supply means, isconstructed and arranged, when positioned in the second position, tocapture into the elongate orifice at least a major proportion of anyfluid skimmed off the first moving forming fabric adjacent the leadingedge of the fabric contacting surface of the skimmer blade.

[0022] In a second broad embodiment this invention seeks to provide aprocess for improving sheet properties and fluid removal in a papermaking machine forming section, having a machine direction and a crossmachine direction, and including a first and a second opposed formingfabric, each of which has a machine side surface and a paper sidesurface, which move together in the machine direction, and a head boxslice which delivers a stock jet into a gap between the paper sidesurfaces of the first and the second forming fabrics, comprising thesteps of:

[0023] (i) discharging the stock jet into the gap between the paper sidesurfaces of the first and the second moving forming fabrics;

[0024] (ii) moving a resiliently mounted skimmer blade, having a leadingedge and a trailing edge, into contact with the machine side surface ofthe first forming fabric;

[0025] (iii) adjusting at least one parameter chosen from the groupconsisting of the pressure pulses generated within the stock, and theamount of fluid skimmed from the machine side surface of the firstforming fabric, by altering the position, or the orientation, or boththe position and orientation, of the fabric contacting surface of the atleast one resiliently mounted blade; and

[0026] (iv) capturing at least a major proportion of any fluid skimmedoff the machine side of the first forming fabric by means of acontrolled level of vacuum applied to an elongate cross-machinedirection orifice adjacent the leading edge of the skimmer blade.

[0027] In a third broad embodiment, this invention seeks to provide aforming section for a paper making machine including a first and asecond opposed forming fabric, each fabric having a machine side surfaceand a paper side surface, including at least one suction assisted fluidskimmer blade carried by a mounting including:

[0028] a vacuum chamber, having an elongate orifice extending in thecross machine direction, to which a controlled vacuum means isconnected;

[0029] a first adjustable support means supporting the vacuum, chamber;

[0030] a second adjustable resilient support means carried by the vacuumchamber and adjacent the first forming fabric; and

[0031] a skimmer blade attached to the second adjustable resilientsupport means, the skimmer blade having a fabric contacting surfaceextending in the cross machine direction including a leading and atrailing edge;

[0032] wherein:

[0033] (a) the first adjustable support means is constructed andarranged to allow the vacuum chamber to be positioned in a firstposition where the skimmer blade is out of contact with the adjacentforming fabric, and a second position where the skimmer blade can be incontact with the first forming fabric;

[0034] (b) the second adjustable resilient support means is constructedand arranged to allow movement of the skimmer blade when the vacuumchamber is in the second position to any point between a first locuswhere the fabric contacting surface of the skimmer blade is out ofcontact with the adjacent forming fabric, and a second locus where thefabric contacting surface of the skimmer blade is pressed into themachine side surface of the adjacent forming fabric;

[0035] (c) the vacuum chamber, together with the vacuum supply means, isconstructed and arranged, when positioned in the second position, tocapture into the elongate orifice at least a major proportion of anyfluid skimmed off the adjacent moving forming fabric adjacent theleading edge of the fabric contacting surface of the skimmer blade; and

[0036] (d) the skimmer blade contacts the machine side of one formingfabric at a point that is between two fixed support elements in contactwith the machine side of the other forming fabric.

[0037] Preferably, when the skimmer blade mounting of this invention isincorporated into a twin fabric forming section, the two fixed supportelements in contact with the machine side of the other forming fabriccomprise at least a part of a forming shoe.

[0038] Preferably, the forming section includes at least one suctionassisted fluid skimmer blade mounting. Alternatively, the formingsection includes more than one suction assisted fluid skimmer blademounting. Additionally, the forming section includes more than onesuction assisted fluid skimmer blade mounting, at least one of which islocated adjacent the machine sides of each of the two forming fabrics.

DETAILED DESCRIPTION OF THE INVENTION

[0039] The invention will now be described with reference to theembodiment shown in the attached schematic drawings in which:

[0040]FIG. 1 shows schematically the general arrangement of a suctionassisted fluid skimmer blade mounting in a forming section;

[0041]FIG. 2 shows in more detail the adjustable mounting of FIG. 1 withthe skimmer blade in contact with a forming fabric.

[0042] Referring first to FIG. 1, the forming section 1 includes twoforming fabrics 2, 3 which move together through the forming section 1in the direction shown by the arrow A. On the machine side of theforming fabric 2 support structures 4, 5 each carry a blade 6, 7attached to the support structure by a conventional dovetail means 8, 9.In FIG. 1 only two blades are shown; a forming section of this type willgenerally include more than two such blades. The attachment shown foreach of these blades is a conventional substantially rigid dovetailstructure; other systems such as a T-bar are known and used. The onlyway the fabric contacting surface, and the orientation, of these bladescan be altered is to remove and then replace them with a differentblade.

[0043] The suction assisted fluid skimmer blade mounting of thisinvention is mounted on the other side of the two forming fabrics fromthe fixed blades 6, 7. The main part of the mounting is a vacuumdrainage box 10. This is supported by a first support means 11. In theconstruction shown, the support means permits rotation of the vacuumdrainage box through a small arc in the directions shown by the arrow B.The position of the vacuum drainage box is controlled by the controlmeans 12, which is discussed further below.

[0044] A controlled level of vacuum is applied to the vacuum drainagebox by the controlled vacuum means shown schematically at 13. Suitabledevices for this purpose are well known. The level of vacuum requiredfor the suction assisted fluid skimmer blade mounting of this inventionis also discussed below. Fluid enters the vacuum drainage box throughthe orifice 14, which extends in the cross machine direction adjacentthe skimmer blade 15. As shown, the skimmer blade attachment 16 includesa conventional dovetail arrangement 17. The skimmer blade 15, togetherwith the attachment 16, is resiliently supported by a second supportmeans shown schematically at 18. The construction of this support meansis shown in more detail in FIG. 2. The vacuum drainage box is shown inFIG. 1 in its first position, at which the skimmer blade 15 is out ofcontact with the forming fabric 3.

[0045] Any suitable device can be used for the control means 12. Aconvenient one is a hydraulic cylinder 120, carried by suitable pivotsas at 121 and 122. In most installations, more than one cylinder, eachwith its own pivots, will be required spread out in the cross machinedirection. Hydraulic control systems for such a set of cylinders arewell known. FIG. 1 shows the vacuum box located in its first position.The precise location for the first position is not important, providedthat it brings the skimmer blade 15 out of contact with the formingfabric 3. The vacuum drainage box 10 is shown in its second position inFIG. 2. This position is controlled accurately by the cooperating stops123, 124 attached respectively to the vacuum assisted drainage box andto a suitably rigid part of the forming section structure, such as abeam carrying the first support 11. At least one of these stops will beadjustable so that the second position for the drainage box 10 can beset accurately. The cooperating stops 123, 124 are set so that when theskimmer blade resilient mounting 18 is fully retracted, the skimmerblade 15 is just out of contact with the forming fabric 3. In order toprovide adequate engagement of the skimmer blade 15 with the formingfabric 3 the resilient mounting 18 will generally provide a range ofmovement in the Z-direction with the drainage box in the second positionof from about 5 mm to about 10 mm.

[0046] Referring now to FIG. 2, the details of the preferred secondadjustable resilient mounting 18 are shown. The mounting 18 is attachedto the vacuum drainage box 10 by a conventional T-bar 19 mated into acorresponding slot 20 in the base 21 of the resilient mounting. Themounting proper comprises essentially four parts: two flexible members22, and 23, and two hose members, 24 and 25. These four parts cooperateas follows when the mounting is activated to move the skimmer blade inthe Z-direction. The two flexible members 22 and 23 are fabricated sothat when there is no pressure in either of the hoses 24 and 25, theskimmer blade is close to, but not in contact with, the forming fabric 3when the vacuum box is in its second position, as determined by thestops 123, 124. Application of pressure to the hoses 24 and 25 moves theskimmer blade in the Z-direction into contact with the forming fabric 3,by bending the flexible members 22 and 23. Since member 22 is secured at26 to the upstream edge of the base member 21, and member 23 is securedto the downstream edge of the flexible member 22 at 27, evenpressurization of the hoses 24 and 25 moves the skimmer blade 15 in amore or less straight line in the Z-direction, into contact with theforming fabric 3, with its face more or less parallel to the, surface ofthe forming fabric. By altering the pressures in the two hoses 24 and 25the orientation of the skimmer blade 15 can be changed, so that eitherthe leading edge 28, or the trailing edge 29, can be pressed into theforming fabric 3. Both the orientation of the blade 15, and the amountof indentation into the forming fabric 3, affect both the pressurepulses generated in the stock between the two forming fabrics and theamount of fluid skimmed from the machine side surface of the formingfabric.

[0047] The mounting 18 also includes two end plates 30 and 31. Theseserve both to minimise penetration of solids from the stock into theinternal spaces between the hoses 24, 25 and the flexible members 22 and23, and to guide the skimmer blade during movement of the mounting.

[0048] In FIGS. 1 and 2 a preferred flexible mounting is shown. Thismounting does not involve any sliding or rotating parts which can becomeobstructed by accumulations of paper making solids. Other knownmountings, such as some of those described by Bubik in U.S. Pat. No.5,262,010, can also be used. As shown in FIG. 2 the mounting 18 utilizesseparate parts for the base 21, the two flexible members 22, 23, and theend plates 30, 31. Depending upon the material chosen for these parts,either three parts as shown can be used, or the whole unit can befabricated as a unitary construction. Where separate parts are used, anysuitable means can be used to attach them together. These parts areconveniently fabricated from fibre reinforced plastic or stainlesssteel. Stainless steel is preferred.

[0049] In order to flex the mounting, pressure is applied to the hoses24 and 25. It is preferred that hydraulic pressure, rather than airpressure, is used for this purpose. It is also necessary that thecontrol system used for the hydraulic or air pressure includes areservoir or the like, so that the mounting is resilient, and can moveto accommodate transient changes in stock thickness. Pressure systemswith this capability are well known for both air and hydraulic use.Since the skimmer blade, together with its resilient mounting, has someflexibility, it is able to respond to local stock thickness variationswhich only extend in the cross machine direction partway across theforming section. The resilient mounting also allows the skimmer blade toapply a more or less uniform pressure in the cross machine direction tothe machine side surface of the forming fabric.

[0050] When the skimmer blade 16 is brought into contact with theforming fabric 3 it will doctor fluid off the machine side surface 32 offabric 3. At least the major proportion of this fluid is captured intothe elongate orifice 14 and travels in the direction shown generally bythe arrow C. To ensure that this occurs, sufficient vacuum is applied bythe controlled vacuum means 13 to the vacuum drainage box 10. Since theelongate orifice 14 is not in contact with the forming fabric, the levelof applied vacuum in the vacuum assisted drainage can be controlled tocapture at least a major proportion of the doctored off fluid without atthe same time extracting fluid from the stock in between the formingfabrics 2 and 3.

[0051] With the skimmer blade in contact with a forming fabric, thenature of the pressure pulses generated within the stock by the skimmerblade are determined by how far the skimmer blade is moved in theZ-direction and indented into the machine side of the forming fabric,together with the orientation of the blade surface relative to themachine side surface path of the forming fabric at that point. Theresilient mounting of the skimmer blade to the vacuum box allows thealteration of each of these variables without any interruption ofproduction on the papermaking machine. A further level of control can beobtained by the use of more than one skimmer blade assembly, comprisinga skimmer blade, its resilient mounting, and a vacuum box. Each assemblycan be activated and deactivated as seen to be necessary to optimizepaper making conditions in the forming section. When more than oneskimmer blade assembly is used, these can be placed on either or bothsides of the two forming fabrics. The or each resiliently mountedskimmer blade assembly will always be located between two fixed bladesin contact with the machine side surface of the other forming fabric,for example between two blades supported by a forming shoe on the otherside of the forming fabrics.

[0052] In the practice of this invention, it is contemplated that thesurface of the skimmer blade will generally be flat. However, in certaincircumstances, the use of a skimmer blade with a contoured profile maybe found to be desirable.

[0053] It is thus apparent that, for any given twin fabric formingsection, some experimentation will often be required to obtain thedesired strength in the pressure pulses generated in the stock, and theamount of fluid doctored off the machine side of the forming fabric bythe skimmer blade. Further, since the position of the skimmer blade inthe Z-direction, and the orientation of the skimmer blade surfacerelative to the path of the machine side surface of the forming fabricat that point are independently adjustable, it becomes far easier toreconfigure the papermaking machine to accommodate a change in productbeing made.

What is claimed is:
 1. A suction assisted fluid skimmer blade mountingfor use in a twin fabric forming section of a paper making machinehaving a machine direction and a cross machine direction, and includingin the forming section a first and a second opposed forming fabric whichmove together in the machine direction, each fabric having a machineside surface and a paper side surface, the mounting including: a vacuumchamber, having an elongate orifice extending in the cross machinedirection, to which a controlled vacuum means is connected; a firstadjustable support means supporting the vacuum chamber; a secondadjustable resilient support means carried by the vacuum chamber andadjacent the elongate orifice; and a skimmer blade attached to thesecond adjustable resilient support means, the skimmer blade having afabric contacting surface extending in the cross machine directionincluding a leading and a trailing edge; wherein: (a) the firstadjustable support means is constructed and arranged to allow the vacuumchamber to be positioned in a first position where the skimmer blade isout of contact with the first forming fabric, and a second positionwhere the skimmer blade can be in contact with the forming fabric; (b)the second adjustable resilient support means is constructed andarranged to allow movement of the skimmer blade when the vacuum chamberis in the second position to any point between a first locus where thefabric contacting surface of the skimmer blade is out of contact withthe first forming fabric, and a second locus where the fabric contactingsurface of the skimmer blade is pressed into the machine side surface ofthe first forming fabric; and (c) the vacuum chamber, together with thevacuum supply means, is constructed and arranged, when positioned in thesecond position, to capture into the elongate orifice at least a majorproportion of any fluid skimmed off the first moving forming fabricadjacent the leading edge of the fabric contacting surface of theskimmer blade.
 3. A forming section for a paper making machine includinga first and a second opposed forming fabric, each fabric having amachine side surface and a paper side surface, including at least onesuction assisted fluid skimmer blade carried by a mounting including: avacuum chamber, having an elongate orifice extending in the crossmachine direction, to which a controlled vacuum means is connected; afirst adjustable support means supporting the vacuum chamber; a secondadjustable resilient support means carried by the vacuum chamber andadjacent the first forming fabric; and a skimmer blade attached to thesecond adjustable resilient support means, the skimmer blade having afabric contacting surface extending in the cross machine directionincluding a leading and a trailing edge; wherein: (a) the firstadjustable support means is constructed and arranged to allow the vacuumchamber to be positioned in a first position where the skimmer blade isout of contact with the adjacent forming fabric, and a second positionwhere the skimmer blade can be in contact with the forming fabric; (b)the second adjustable resilient support means is constructed andarranged to allow movement of the skimmer blade when the vacuum chamberis in the second position to any point between a first locus where thefabric contacting surface of the skimmer blade is out of contact withthe adjacent forming fabric, and a second locus where the fabriccontacting surface of the skimmer blade is pressed into the machine sidesurface of the adjacent forming fabric; (c) the vacuum chamber, togetherwith the vacuum supply means, is constructed and arranged, whenpositioned in the second position, to capture into the elongate orificeat least a major proportion of any fluid skimmed off the adjacent movingforming fabric adjacent the leading edge of the fabric contactingsurface of the skimmer blade; and (d) the skimmer blade contacts themachine side of one forming fabric at a point that is between two fixedsupport elements in contact with the machine side of the other formingfabric.
 4. A forming section according to claim 3 wherein the or eachthe skimmer blade mounting is located on the other side of the formingfabrics from a forming shoe.
 5. A forming section according to claim 3wherein the forming section includes one suction assisted fluid skimmerblade mounting.
 6. A forming section according to claim 3 wherein theforming section includes more than one suction assisted fluid skimmerblade mounting.
 7. A forming section according to claim 6 wherein atleast one skimmer blade mounting is located adjacent the machine sidesof each of the two forming fabrics.
 8. A skimmer blade mountingaccording to claim 1 wherein the second resilient mounting isconstructed and arranged to allow the orientation of the skimmer bladerelative to the machine side surface of the forming fabric to bealtered.
 9. A skimmer blade mounting according to claim 8 wherein thesecond resilient mounting is constructed and arranged to allow eitherthe surface of the skimmer blade, or the leading edge of the skimmerblade surface, or the trailing edge of the skimmer blad surface, to bepressed into the forming fabric.
 10. A skimmer blade mounting accordingto claim 1 wherein the second resilient mounting means comprises aflexible mounting means, together with a means to flex the flexiblemeans and urge the skimmer blade into contact with the forming fabric.11. A skimmer blade mounting according to claim 10 wherein the secondresilient mounting means comprises a flexible mounting means, togetherwith a pressurized means to flex the flexible means and urge the skimmerblade into contact with the forming fabric.
 12. A skimmer blade mountingaccording to claim 11 wherein the pressurized means is chosen from thegroup consisting of a hydraulic means and a pneumatic means.